Production of multilayer compacted granular products



July 12, 1960 G. J. N. CHERRY ETAL 2,944,307

PRODUCTION OF MULTILAYER COMPACTED GRANULAR PRODUCTS Filed ,Jan. 28, 1958 lNvaN-roms GBo sEJO-SEPH NN- -CHERRY DAYHD Rut-wan THOMAS B) Guam, figM md 044a ATTYS- United States Patent.

2,944,301 v c PRODUCTION oF'MULTILAYER CQMPACTEQ George Joseph Nall Cherry, and David Richard Thomas, Birmingham, nd, s gn rs Fou ry S es.

International Limited, Birmingham, England, a British This invention relates to process'es'and apparatus for the production of multilayer products .in which; ach layer is formed'of compacted granularmaterial. r

layers is exceptionally good but there is noneedfor 2 "ice 7 2 a n ay duplex s ares tr aesi ansfsz'mtherm materials are obtained in which the anchorage '0 "the arate handling of the reen sand shape."

. According furtber to the present inventionythere is provided apparatus for theproduction of prodilcts'com prising two layers of compacted granular material united together at their interface which comprises chamber,

a thin removable partition dividing said chamber'inttflvQq compartments, a jolting deviceforioltingsaidffch her and means for withdrawing the said removable galililtlqll while continuing the jolting f action,

The method and apparatus of the invention will now; be illustrated with reference to theproduetion of a duplex sleeve, i.e. one consisting of't wo tactiir'g' hceri'tric cylinders," e.g.' of sand and exothermic material espec tively, anchored together at their interface. I

It is of particular value in the production of materials for foundryuse and more particularly'in :the p'roduction' of multilayer sleeves and the like usdas lihings for hot top boxes, the heads of. ingot mouldsfand the'like. It will therefore be described with'special reference to this especial application. I It is known practice in the production ofi' metal castings or ingots to locate an exothermic mixturejlusually'comprising aluminium and an oxidising agent'gas a lining for the riser cavities, feeding head cavities or headboxes.

A particularly valuable-type of exothermic mixture for the purpose is described in United 'Sta'tes'Patent' No.

2,591,105 and consists of aluminium, a quantity. of oxidise ing agent insutficient to oxidise all the aluminium and a' proportion of 1 to 5% of a fluoride; usually alsoflvith a posed; e.g.' mixtures ssimilarto those 'ofsthezsaid patent in' which-the proportion of fluoride may. be -as 'l'ittle as'.0.5.%

Suitable apparatus for carry'ng out the method is illustrated in the accompanying drawing, it beifig'nder stood that thelappal'atus" stands on the platfo'r 0P5 j olting machine.

Referring 'to this drawing the apparatus'comprises a base plate'2 (which rests on thesaid platform 1)? "Formed? with the base plate2 is an upstanding hollow core former' 3. Mounted concentrically with the core forin'er "Sis a core box '4. In the annulusbetweenthe core former 3 and the core box '4: is a removable thin walled cyl'in 6r 5. This is connected by across bar 6 'atits'upperoperi end we cap member 7 adapted to fit over the upper o'periend of'the core former 3 and is further connected tea plunger8 of a fluid-operated,'e.g. hydraulic orpneuma c,

cylinder 9. TheCapmeinber7Iis"provided'with a tl Many other exothermic mixtures haveibeenr'proa' plate 10 and there are alsoprovid'ed electro-inagnetsl'l' fed with currents via btls-ba'r'J-S and cooperating with the plate 1t). A detachablehopp'er 1-2 is onri'ecte' e:

upper edge of the core box '4. 1 v u The method of operation is 'as follows. The apparatus] is assembled as shown and the current'td the ele'ctro i magnets is switched on. These, by attractingth'e steelplate 10, hold the cap 7 and the cylinder'5 infposition as shown in' the'd'rawing. 'Sand "is fed via the hopper "12 to fill theannularspac'e between the core'box land whichthe exothermic material isiliackedby a ayer 'of re-i fractoryor heat-insulatingmaterial. F g

The presentinvention is concerned with-:an improved: method of forming such multilayer materialse :Ai most convenient backing material is-sand and th'e'invention willthe cylinder 5' Simultaneouslyexothermic "composition is fed are the open (end of the zyl inder" 5, pa'sses over the cap 7 and the annulus between" the cor former 3'and the cylinders."

, 1 During the filling operation the joltingtable is mainbe described with particularreference to the use-of sa'nd;

though it is to be understoodthat it isnot so limitedi-l- Currently there aretwo maintechniques employed in:

the production of duplex materials of the type referredtoz In one method the sand is rammcd intora space tot-the desired shape, a lining of exothermic material is then applied and the whole assembly, strayed method a good anchorage is eh vll iwgenfthc sand'and the exothermic material but the method is "diflicult since it necessitates? handling thesand shape in its green '(i.e.'

unstoved) condition. V.

Alternatively, therefore, the;sand':shape cane v beforeithe exothermic. layer, is. tapplied""but whllststhis avoids the necessity of handling the green and shape it results in less efiicient anchorage betweenthe layers.

' According to'the presentin vention there is provided aprocess for making a product comprising at'least two layers formed of compacted granular material, the layers being united at their interface, which comprises feeding the materials which are to form two said'layers separately i'nto adjacent compartments'separated' bya'removable thin partition, compacting each in its own compartment by a jolting action, removing the said partition and contwo layers become united at their interface.

" materials, '7

tinuing the saidjoltingactionruntilgthe materials of the tained in motion so that thematerials compactlin their separateadjacentarinuli." his usually round ilesirable't'o stop the 'jolting action 1 after" a period,' td allow-the annulr' to be topped'upf ile; additionalmaterial addedto-make up- 'for the loss of volume-"due t'oithe compacting the Then, with the jol ti n g action maintained, thecurrent to the electr'O-magnetsfis'switched ofl fand th'e valvc t'o' the cylinde'r 9 is openedtocause the "plunger 8=to move upwards. This-is effected slowly; 'softh'afthe cylinder5 is only slowly withdrawn froni its 'i zkbsition between the compacted layers in the adjacent annuli. The co'fitinuedi gether at their interface. If necessary or desirablev addi jtional sand and exothermic material may be fed in to "take up the smalltdrop in level which results from the sand and exothermic material filling the space previously occupied by the thin metal cylinder 5.

-When thecylinder 5 is wholly withdrawn it is removed, together with the cap 7 and the hopper 12 leavthe compacted materials is separated, resting on the board. It may then be stoved to impart to it desirable properties of rigidity.

, Since the sand and exothermic material are simultaneously stoved a good anchorage between them is achieved.

Moreover, the method has the advantage of speed since the two layers of the sleeve are formed simultaneously and not in succession as in previous methods.

It is to be understood that while the invention has been described with reference to the production of a duplex sleeve, it may also be applied to the production of such two layer assemblies in other shapes, including the production of flat or curved duplex slabs or tiles and, by the provision of aniappropriate number of partitions, to the production of products having more than two layers.

We claim as our invention:

1. Apparatus for the production of hollow cylindrical products comprising two annular layers united together at their interface which comprises a hollow cylindrical core former and a core box of hollow cylindrical inner configuration defining an annular space therebetween, a removable thin cylindrical partition within said annular space whereby said annular space is divided into two adjacent annular spaces, a cover for the open end of said core former connected to said thin cylindrical partition, separately operable releasable means within the core former for, holding the said cover close on said corc former and for raising said cover and concomitantly said cylindrical partition, means for feeding separate granular materialsinto the said two annular spaces and means for joltingthe whole apparatus continuously.

2. Apparatus for the production of hollow cylindrical.

productscomprising two annular layers united together at their'interface which comprises a hollow cylindrical coreformer and a core box of hollow cylindrical inner configuration defining an annular space therebetween, a removable thin cylindrical partition within said annular space whereby said annular space is divided into two adjacent annular spaces, a cover for the open end of said core former having magnetisable material therein, electro-magnetic means within the core former for co-operation with said magnetisable material to hold the said cover close on said core former, separately operable fluidoperated pressure apparatus for raising said cover and concomitantly said. partition, and means for jolting the whole apparatus continuously.

3. Apparatus for the production of hollow products comprising two annular layers united together at their interface, which comprises a hollow core former and a core box of hollow inner configuration having an annular space therebetween, a removable thin partition within said annular space whereby said annular space is divided into two adjacent annular spaces, a cover for the open end of said core-former connected to said thin partition, separately operable releasable means within the core-former for holding the cover close on said coreformer and for raising said partition, means for feeding separate granular materials into the said two annular spaces and, means for jolting the whole apparatus continuously.

4. Apparatus for the production of hollow products comprising two layers united together at their interface, which apparatus comprises, in combination, a hollow core-former and a core box of hollow inner configuration defining an annular space therebetween, a removable thin partition within said annular space'dividing the same into two adjacent annular spaces, a cover for the open 1 end of said core-former, means within the corc former for releasably holding the cover close on thecore-fori er,; means supporting said partition on said eover, means for feeding separate granular materials into said two annular spaces, means within said core-former engageable with said supporting means for raising said 7, nular space dividing the same into two adjacent annular spaces, .aigenerally conical cover for the open end of said core-former defining an upwardly sloping surface, means within the core-former for releasably holding the cover close on the core-former, means supporting said partition on the upper end of said conical cover, means for feeding separate granular materials into said two annular spaces, means within said core-former engageable with said supporting means for raising said partition, and means for jolting the whole apparatus continuously during thefeeding of said materials and the raising of said partition.v

6. Apparatus for the production of hollow cylindrical products-comprising two layersunited together at their interface;whichapparatus comprises, in combination, a

i hollow. cylindrical core-former and a core box of hollow cylindrical inner configuration defining an annular space therebetween, means defining a. hopper on said core box, a removable thin partition withinsaid annular space dividing the same into two adjacent annular spaces, a genorally conical cover fortheopen end of said core-former definingan upwardly'sloping surface terminating in an upper horizontal surface, meanswithin the core-former for releasably holding the cover close on the core-former, means supporting said ipartitionon the upper surface of .7 saidconical cover, means for feeding separate granular materials over-saidhopper and said conical surface into said .two :annular spaces,- a plunger extending through said core-former and conical cover into engagement with said supporting means, means for raising said plunger and thereby said partition, and means for jolting the whole apparatus continuously during the feeding of said materials and the raising of said partition.

References Cited in the file of this patent UNITED STATES PATENTS 965,150 Atterbury July 26, 1910 1,171,579 Atterbury Feb. '15, 1916 2,591,105 Strauss et al. Apr. 1, 1952 2,821,000

Noveau Jan.- 28, 1958 

